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package SecureUtil;

import java.security.MessageDigest;

/**
 *
 * @author Gwang
 */
public class HashHelper {
    public static byte[] SHA1(byte[] bytes) throws Exception  {
        MessageDigest md;
        md = MessageDigest.getInstance("SHA-1");
        byte[] sha1hash = new byte[40];
        md.update(bytes);
        sha1hash = md.digest();
        return sha1hash;
    }
    public static String SHA1String(byte[] bytes) throws Exception  {
            return HexString(SHA1(bytes));
    }
    public static String HexString(byte[] data) {
        StringBuffer buf = new StringBuffer();
        for (int i = 0; i < data.length; i++) {
            int halfbyte = (data[i] >>> 4) & 0x0F;
            int two_halfs = 0;
            do {
                if ((0 <= halfbyte) && (halfbyte <= 9))
                    buf.append((char) ('0' + halfbyte));
                else
                    buf.append((char) ('a' + (halfbyte - 10)));
                halfbyte = data[i] & 0x0F;
            } while(two_halfs++ < 1);
        }
        return buf.toString();
    }
}
